A page can change. Its edition should not.
The living notebook and its fixed editions serve different purposes.
The ordinary notebook address points to the current explanatory text. An edition address includes a named snapshot and continues to serve that snapshot’s content when the living notebook is revised.
What is preserved
- The notebook and chapter identity.
- The chapter introduction, text, figures and structured content.
- The reference list and its recorded resource links.
- The edition date and a SHA-256 content fingerprint.
Checking a citation
Download the page’s citation metadata to retrieve the canonical JSON payload and the expected SHA-256 value. Recomputing the digest of that payload checks content identity. It cannot establish the truth of the content or the continued availability of an external source.
Cuntz · Released record#
What does the model’s SHA-256 prove?
A checksum is a fingerprint calculated from bytes. Fixity checking compares that fingerprint with a trusted expected value to detect changed or mismatched files.
Work through the example 3 STEPS
The published GLB source for this notebook has SHA-256 beginning 19527c2188b08d85. The display derivative has a different digest because its texture and encoding were changed.
Compare like with like
Check the complete source GLB digest against the exact source realization. Compare the website derivative against its own expected digest, not against the source GLB’s digest.
Notice byte-changing edits
A texture conversion or mesh encoding change produces a different file identity. Even reformatting a JSON manifest can change its exact-byte hash without changing its parsed meaning.
Keep the scientific question separate
Matching bytes establish which representation was obtained. The digest does not verify the model’s physical scale, the pipe measurement method or a claim about the sound of 1610.
BASIS FOR THIS EXAMPLE
- Cuntz Positiv · VAO 0.5.0-rc.2 ↗
Published manifest: identities, measurement observations, realization digests, profiles and rights. Exact examples checked against this release.
- VAO Standard 0.5.0 ↗
The standard contract is separate from the Cuntz dataset content version 0.5.0-rc.2.
This website verifies the model’s expected byte length and full SHA-256 before passing it to the renderer. That is a file-identity check, not a VAO conformance report.
The useful distinction. Fixity makes evidence identifiable; it does not independently validate the evidence’s interpretation.
A correction creates a successor
A living page can improve its explanation or correct a mistaken release description. The earlier edition should continue to identify what a reader could cite at that time. This makes it possible to distinguish an editorial correction from a changed research artifact, and to explain why two quotations or references differ.
| Change | Consequence for this website |
|---|---|
| Text, examples or resource descriptions | Publish a new content edition and preserve earlier snapshots. |
| Referenced diagram definitions | Include the changed definitions in the new chapter fingerprint. |
| Colour, typography or navigation styling | The presentation can change without changing the structured chapter identity. |
| An external resource changes | The notebook citation remains fixed; verify the external version separately. |
Cuntz · Illustrative scenario#
Which Cuntz identifier belongs in a citation?
Versioned citation separates the physical subject, the released research object and the explanation or derived artifact actually used.
Work through the example 3 STEPS
A reader uses the notebook’s model to discuss a geometry, while another uses the 1281 mm workbook observation. Their references should identify different evidence even though both concern Cuntz.
Identify the release
Use version DOI 10.5281/zenodo.22151203 for the inspected dataset. Record the specific realization or observation, rather than citing only the project community.
Identify what was used
For the web preview, retain the derivative’s digest and transformation note. For the observation, identify the pipe, property, source cell and workbook realization.
Cite the explanation separately
Use “Cite this page” for the notebook’s fixed edition. Its fingerprint identifies the explanation; it does not replace the source dataset or model fingerprint.
BASIS FOR THIS EXAMPLE
- Cuntz Positiv · VAO 0.5.0-rc.2 ↗
Published manifest: identities, measurement observations, realization digests, profiles and rights. Exact examples checked against this release.
- VAO Standard 0.5.0 ↗
The standard contract is separate from the Cuntz dataset content version 0.5.0-rc.2.
The dataset content version 0.5.0-rc.2, VAO format version 0.5.0 and website edition are separate version systems.
The useful distinction. A citation chain lets a reader recover both the evidence and the interpretation.
Verify a downloaded citation record
Python standard library · save the downloaded metadata as citation.json
import hashlib
import json
from pathlib import Path
record = json.loads(Path("citation.json").read_text(encoding="utf-8"))
payload = record["canonicalPayload"].encode("utf-8")
actual = hashlib.sha256(payload).hexdigest()
if actual != record["sha256"]:
raise SystemExit("Content fingerprint does not match")
print("Verified:", record["edition"], actual)Hash the supplied canonicalPayload string exactly, without pretty-printing it or converting its line endings. The structured payload is also provided for inspection. The comparison verifies consistency with the expected digest in that record; independently retained metadata or an archived copy is needed if you want a reference beyond the current host.
Preservation extends beyond the website
Versioned local URLs and checksums make these notebooks citable and inspectable, but continued access still depends on hosting and retained editions. A separately archived release could provide an additional preservation location. No notebook DOI or independent repository deposit is implied until such a deposit has actually been made.
Page editions 2026-09-r6 ↓
Read a fixed snapshot of this chapter, or return to the current notebook.
Edition 2026-09-r6 · SHA-256
02384a7cbe0bPage metadata ↗